In a press conference on Tuesday, President Barack Obama called the bombings an “act of terrorism” and announced that he has authorized all applicable government resources to the investigation.

On Monday, the broadcast and cable news networks deployed its biggest name reporters to the scene, including ABC’s Terry Moran, CNN’s Anderson Cooper and Chris Cuomo, Fox News’ Shepard Smith, as well as NBC’s Matt Lauer and Lester Holt.

For Tuesday, coverage centers on the search for the organization or individual behind the attack, the wellbeing of those who were injured and the nationwide increase in security. Fox News Channel is paying special attention to the use of pressure cookers in the bombs and the investigation of cell phone records.

Here’s how the networks are covering Day 2’s developments.

ABC

– A special one-hour edition of “World News with Diane Sawyer.” Sawyer speaks with Dr. Dave King, a trauma surgeon at Mass General in Boston. In addition, Boston Mayor Thomas Menino and former New York City Mayor Rudy Giulini come together for a special mayor-to-mayor conversation with Sawyer.

– Additional platforms: CNN.com/live and the CNN Apps for live streaming of the breaking news as it unfolds, CNN.com’s breaking news blog, This Just In, for the latest details and reaction. Users can also share stories and images of the explosions through CNN iReport.

– Additionally from Boston, FNC's Bill Hemmer is anchoring and reporting. Molly Line and Rick Leventhal will provide updates from a location near where the explosions occurred and Mike Tobin will cover the latest from Massachusetts General Hospital.

– From New York, Julie Banderas and Eric Shawn will be live from Time Square to discuss the security around the city and Douglas Kennedy will provide updates on personal stories of the victims.

– From London, FNC correspondent Amy Kellogg will offer details on international security.

NBC

– TUESDAY: 6:30 p.m. ET: Brian Williams will anchor a special edition of “NBC Nightly News” live from Boston

– Wednesday: On "Today," Matt Lauer and Savannah Guthrie will co-anchor live from New York. Natalie Morales and Lester Holt will report live from the ground in Boston. Correspondents Kerry Sanders and Katy Tur will also be live from Boston locations. Correspondents Pete Williams and Tom Costello will be reporting live from Washington, DC.